// g2o - General Graph Optimization
// Copyright (C) 2011 R. Kuemmerle, G. Grisetti, H. Strasdat, W. Burgard
// All rights reserved.
//
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// met:
//
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#ifndef G2O_BASE_VARIABLE_SIZED_EDGE_H
#define G2O_BASE_VARIABLE_SIZED_EDGE_H

#include <iomanip>
#include <iostream>
#include <limits>

#include "base_edge.h"
#include "g2o/config.h"
#include "g2o/stuff/misc.h"
#include "robust_kernel.h"

#ifdef G2O_USE_VENDORED_CERES
#include "g2o/EXTERNAL/ceres/fixed_array.h"
#else
#include <ceres/internal/fixed_array.h>
#endif

namespace g2o {

/**
 * \brief base class to represent an edge connecting an arbitrary number of
 * nodes
 *
 * D - Dimension of the measurement
 * E - type to represent the measurement
 */
template <int D, typename E>
class BaseVariableSizedEdge : public BaseEdge<D, E> {
 public:
  /**
   * \brief helper for mapping the Hessian memory of the upper triangular block
   */
  struct HessianHelper {
    Eigen::Map<MatrixX> matrix;  ///< the mapped memory
    bool transposed;             ///< the block has to be transposed
    HessianHelper() : matrix(0, 0, 0), transposed(false) {}
  };

 public:
  static constexpr int Dimension = BaseEdge<D, E>::Dimension;
  typedef typename BaseEdge<D, E>::Measurement Measurement;
  typedef MatrixX::MapType JacobianType;
  typedef typename BaseEdge<D, E>::ErrorVector ErrorVector;
  typedef typename BaseEdge<D, E>::InformationType InformationType;
  typedef Eigen::Map<MatrixX, MatrixX::Flags & Eigen::PacketAccessBit
                                  ? Eigen::Aligned
                                  : Eigen::Unaligned>
      HessianBlockType;

  BaseVariableSizedEdge() : BaseEdge<D, E>() {}

  virtual void linearizeOplus(JacobianWorkspace& jacobianWorkspace);

  /**
   * Linearizes the oplus operator in the vertex, and stores
   * the result in temporary variable vector _jacobianOplus
   */
  virtual void linearizeOplus();

  virtual void resize(size_t size);

  virtual bool allVerticesFixed() const;

  virtual void constructQuadraticForm();

  virtual void mapHessianMemory(number_t* d, int i, int j, bool rowMajor);

  using BaseEdge<D, E>::computeError;

 protected:
  using BaseEdge<D, E>::_measurement;
  using BaseEdge<D, E>::_information;
  using BaseEdge<D, E>::_error;
  using BaseEdge<D, E>::_vertices;
  using BaseEdge<D, E>::_dimension;

  std::vector<HessianHelper> _hessian;
  std::vector<JacobianType, Eigen::aligned_allocator<JacobianType> >
      _jacobianOplus;  ///< jacobians of the edge (w.r.t. oplus)

  void computeQuadraticForm(const InformationType& omega,
                            const ErrorVector& weightedError);

 public:
  EIGEN_MAKE_ALIGNED_OPERATOR_NEW
};

#include "base_variable_sized_edge.hpp"

}  // end namespace g2o

#endif
